The Institute of Electrical and Electronics Engineers (IEEE) 802.16m communication system is a representative example of mobile communication systems, and a process of generating a service flow by an IEEE 802.16m communication system will now be described with reference to FIG. 1.
FIG. 1 schematically illustrates a process of generating a service flow by a typical IEEE 802.16m communication system.
In order to provide a service to an Advanced Mobile Station (AMS) in an IEEE 802.16m communication system, an initial signal transmission/reception procedure in the network layer, including acquisition of an Internet Protocol (IP) address, is necessary for an initial access procedure in a wireless network. Therefore, the initial access procedure in a wireless network includes a process of generating a service flow in order to transmit/receive messages for the initial signal transmission/reception procedure in the network layer.
Referring to FIG. 1, the IEEE 802.16m communication system includes a plurality of AMSs, which include AMS#1 111-1, AMS#2 111-2, and AMS#3 111-3, an Advanced Base Station (ABS) 115, an Access Service Network-Gateway (ASN-GW) 119, an Application Server (AS) 121, a Policy Charging Rules Function (PCRF) server 123, and an Authorization, Authentication, and Accounting (AAA) server 125. Each of AMS#1 111-1 to AMS#3 111-3 generates an individual transport connection and an individual service flow. Specifically, AMS#1 111-1 generates transport connection#1 113-1 and service flow#1 117-1, AMS#2 111-2 generates transport connection#2 113-2 and service flow#2 117-2, and AMS#3 111-3 generates transport connection#3 113-3 and service flow#3 117-3. Therefore, the ABS 115 is connected to the ASN-GW 119 by using a service flow generated for each AMS, and each of the AMSs is connected to the ABS 115 by using a transport connection mapped to a corresponding service flow.
In a state in which the AMSs have been connected with the ASN-GW by using the service flows and the transport connections, data is transmitted to the AMSs according to the process as described below.
First, when the AS 121 transmits data to AMS#1 111-1, the data is transmitted to AMS#1 111-1 through a path of the AS 121—the ASN-GW 119—service flow#1 117-1—the ABS 115—transport connection#1 113-1—AMS#1 111-1.
Second, when the AS 121 transmits data to AMS#2 111-2, the data is transmitted to AMS#2 111-2 through a path of the AS 121—the ASN-GW 119—service flow#2 117-2—the ABS 115—transport connection#2 113-2—AMS#2 111-2.
Third, when the AS 121 transmits data to AMS#3 111-3, the data is transmitted to AMS#3 111-3 through a path of the AS 121—the ASN-GW 119—service flow#3 117-3—the ABS 115 —transport connection#3 113-3—AMS#3 111-3.
Hereinafter, a process of generating a service flow by a typical IEEE 802.16m communication system will be described with reference to FIG. 2.
FIG. 2 is a signal flow diagram of a process for generating a service flow by a typical IEEE 802.16m communication system.
Referring to FIG. 2, an AMS 211 acquires downlink (DL) channel information, performs a Medium Access Control (MAC) synchronization, and then acquires uplink (UL) channel information, in cooperation with an ABS 213 (step 219). Thereafter, the AMS 211 and the ABS 213 perform initial ranging (step 221). Specifically, the AMS 211 transmits an Advanced Air Interface Ranging Request (AAI_RNG-REQ) message to the ABS 213. Upon receiving the AAI_RNG-REQ message from the AMS 211, the ABS 213 transmits an Advanced Air Interface Ranging Response (AAI_RNG-RSP) message, which is a response message to the AAI_RNG-REQ message, to the AMS 211.
After performing the initial ranging with the ABS 213 in the way described above, the AMS 211 transmits an Advanced Air Interface Subscriber Station Basic Capability Request (AAI_SBC-REQ) message to the ABS 213 (step 223). Upon receiving the AAI_SBC-REQ message from the AMS 211, the ABS 213 transmits an AMS Pre-Attachment request (AMS_PreAttachment_REQ) message to the ASN-GW 215 in order to notify the ASN-GW 215 that the AMS 211 has accessed the network (step 225). Upon receiving the AMS_PreAttachment_REQ message, the ASN-GW 215 transmits an AMS Pre-Attachment response (AMS_PreAttachment_RSP) message, which is a response to the AMS_PreAttachment_REQ message, to the ABS 213 (step 227). Upon receiving the AMS_PreAttachment_RSP message from the ASN-GW 215, the ABS 213 transmits an Advanced Air Interface Subscriber Station Basic Capability Response (AAI_SBC-RSP) message, which is a response message to the AAI_SBC-REQ message, to the AMS 211 (step 229). The AAI_SBC-RSP message includes information on authentication policy.
Furthermore, after transmitting the AAI_SBC-RSP message to the AMS 211, the ABS 213 transmits a Pre-Attachment acknowledgement (AMS_PreAttachment_ACK) message, which is a response message to the AMS_PreAttachment_RSP message, to the ASN-GW 215 (step 231).
Upon receiving the AMS_PreAttachment_ACK message from the ABS 213, the ASN-GW 215 performs, in cooperation with the AAA server 217, an Extensible Authentication Protocol (EAP) authentication procedure (step 233). After the EAP authentication procedure, the ASN-GW 215, the ABS 213, and the AMS 211 perform a key exchange procedure (step 235).
After the key exchange procedure, the AMS 211 transmits an Advanced Air Interface Registration Ranging Request (AAI_REG-REQ) message to the ABS 213 (step 237). Upon receiving the AAI_REG-REQ message from the AMS 211, the ABS 213 transmits an AMS Attachment Request (AMS_Attachment_REQ) message to the ASN-GW 215 (step 239). The AMS_Attachment_REQ message includes registration context and an identifier (ID) of the ABS 213.
Upon receiving the AMS_Attachment_REQ message, the ASN-GW 215 transmits an AMS Attachment response (AMS_Attachment_RSP) message, which is a response message to the AMS_Attachment_REQ message, to the ABS 213 (step 241).
Upon receiving the AMS_Attachment_RSP message, the ABS 213 transmits an Advanced Air Interface Registration Ranging Response (AAI_REG-RSP) message, which is a response message to the AAI_REG-REQ message, to the AMS 211 (step 243).
When registration of the AMS 211 is completed through steps 237 to 243 as described above, a procedure for generating a service flow is performed. That is, the ASN-GW 215 transmits a Path Registration Request (Path_REG_REQ) message to the ABS 213 (step 245). The Path_REG_REQ message includes Quality of Service (QoS) parameters for generation of a service flow.
Upon receiving the Path_REG_REQ message, the ABS 213 transmits an Advanced Air Interface Dynamic Service Addition Request (AAI_DSA-REQ) message to the AMS 211 (step 247). Upon receiving the AAI_DSA-REQ message, the AMS 211 transmits an Advanced Air Interface Dynamic Service Addition Response (AAI_DSA-RSP) message, which is a response message to the AAI_DSA-REQ message, to the ABS 213 (step 249). Upon receiving the AAI_DSA-RSP message, the ABS 213 transmits a Path Registration Response (Path_REG_RSP) message, which is a response message to the Path_REG_REQ message, to the ASN-GW 215 (step 251). Furthermore, the ABS 213 transmits an Advanced Air Interface Dynamic Service Addition Acknowledgement (AAI_DSA-ACK) message, which is a response message to the AAI_DSA-RSP message, to the AMS 211 (step 253).
Furthermore, the ASN-GW 215 transmits a Path Registration Acknowledgement (Path_REG_ACK) message, which is a response message to the Path_REG_RSP message, to the ABS 213 (step 255).
As described above, the IEEE 802.16m communication system independently generates and maintains a service flow for each AMS. For example, even when thousands of AMSs intermittently transmit a very small quantity of data, the IEEE 802.16m communication system independently generates and maintains service flows for the thousands of AMSs.
Such an independent generation and maintenance of service flows for the AMSs, which intermittently transmit a very small quantity of data, may cause unnecessary waste of resources, including memory resources and state management resources, in view of the network.